ECG and EKG Interpretation: The Five-Step Method

Introduction

• Presenter: Eddie Watson
• Platform: ICU Advantage
• Focus: Five-step method for interpreting ECGs/EKGs.
• Objective: Simplify ECG interpretation to diagnose patient conditions effectively.

Basics of ECG Interpretation

ECG Grid Paper

• Small Boxes:
  • Represent 0.04 seconds each.
• Large Boxes:
  • Comprised of 5 small boxes (0.20 seconds total).
• Time measurement is crucial for interpreting ECGs.

Rhythm Strips

• Six-second Strip:
  • Contains two sets of 15 large boxes.
  • Important for determining heart rate.

Normal Sinus Rhythm Components

• Isoelectric Line:
  • Represents baseline or neutral charge.
• P Wave:
  • Represents atrial depolarization initiated by SA node.
• QRS Complex:
  • Represents ventricular depolarization.
  • Composed of Q wave, R wave, S wave.
• T Wave:
  • Represents ventricular repolarization.

Intervals of Interest

• PR Interval:
  • Measured from start of P wave to start of QRS.
  • Normal range: 0.12 to 0.20 seconds.
• QRS Complex Duration:
  • Measured from start of Q wave to end of S wave.
  • Normal range: 0.06 to 0.10 seconds.

ST Segment

• Importance:
  • Can indicate myocardial ischemia or infarction if elevated or depressed.

Five-Step Method for ECG Interpretation

Step 1: Identify P Waves and QRS Complexes

• Check for P wave presence and uprightness.
• Ensure a P wave precedes every QRS complex.

Step 2: Measure the Intervals

• PR Interval:
  • Use the grid to measure time.
• QRS Complex:
  • Ensure it’s less than 0.12 seconds.

Step 3: Determine Rhythm Regularity

• Use index card method to check spacing of R waves.
• Identify as regular or irregular rhythm.

Step 4: Determine Heart Rate

• Methods:
  • Six-Second Method: Count QRS in a six-second strip, multiply by 10.
  • Big Box Method: 300 divided by number of big boxes between QRS complexes.
  • Little Box Method: 1500 divided by number of small boxes between QRS complexes.
  • Sequence Method: Use a sequence to estimate heart rate with big box count.
• Normal Rate: 60-100 bpm.

Step 5: Interpret the Rhythm

• Use all gathered data to identify rhythm.
• Normal Sinus Rhythm Criteria:
  • Upright P waves, consistent P-QRS relationship.
  • PR interval: 0.12 to 0.20 seconds.
  • QRS duration: Less than 0.12 seconds.
  • Regular rhythm and rate between 60-100 bpm.

Conclusion

• Understanding and interpreting ECGs can be lifesaving.
• Next Steps: Learn about various arrhythmias in upcoming lessons.
• Importance of timely interpretation for urgent medical intervention.
• Call to Action: Like, subscribe, and follow up with the next lesson in the series.